Typewriting machine



March 6, 1945. I WALKER ETAL 2,371,083

TYPEWRITING MACHINE Filed June 17, 1943 3 Sheets-Sheet 1 C/iarles l/lker ll/z'llard H. ll/ade INVENTORS.

3 Sheets-Sheet 2 c. WALKER ET AL 'ITYPEWRITING MACHINE Filed June 17, 1943 March 6,1945.

' a a C/iar lca ZI/alkcr Zl/z'llqrd H- Zl/ado INVENTORS. I BYZ g f i ATTORNEY.

March 6, 1945. c. WALKER EIAL 2,371,083

TYPEWRITING MACHINE Filed June 17, 1943 5 Sheets-Sheet 3 Cfiarles ll/lker INVENTORS.

ATTORNEY.

Patented Mar. 6, 1945 2,311,083 TYrEwm'rING momma Charles Walker, Syracuse, N. Y., and Willard H. Wade, Washington, D. 0., asslgnors to L. C. Smith & Corona Typewriters, Inc., Syracuse, N. Y., a corporation of New York Application June 17, 1943, Serial No. 491,088

6 Claims.

The invention relates to improvements in typewriting machines and, more particularly, to improvements in power actuated back spacing means for such machines.

The principal object of the invention is to provid in a typewriting machine improved means for reversely stepping one letter space a travelling carriage or support which is normally controlled by an escapement or other means to move in the opposite direction longitudinally of the printing line of the machine one letter space per character typed or per operation of a letter spacing bar of the machine. The carriage or support in most kinds of typewriting machines is a paper carriage, but in some kinds of machines it carries the type bars or other impression making means of the machine instead of the paper.

Further important objects of the invention are to provide an improved back spacing mechanism for typewriting machines whereby the force for reversely stepping the carriage is taken from a shaft or other rotary element which is constantly rotated at high speed, as by an electric motor, while the machine is in use, and to provide, in such a back spacing mechanism, means positively connective with the shaft or element for a single revolution only of the shaft or element .to first impart a fixed back spacing throw to a reciprocal back spacing element or dog by power from said shaft or element and to then impart a biased restoring movement (as by spring means) to said back-spacing element or dog to a normal idle position during each cycle of connection of said means with said constantly rotating shaft or v element.

' vance and return horizontal travel transversely Figure 1 is a fragmentary top plan view of a Figure 4 is a detail sectional view on the line 4--4 of Figure 1.

Figure 5 is a view similar to Figure 4, but showing the back spacing mechanism in operation.

of the machine, the usual roller platen l2 being journaledin the carriage and extending horizontally transversely of the machine. The carriage is advanceable one letter space per letter printed or per operation of the space bar of the machine as usual by power from the usual spring drum (not shown) under control of the usual escape- I ment mechanism.

In the known machine the means whereby the letter space advance of the-carriage is effected includes the usual feed rack I3 fixed to the carriage and extending horizontally transversely of the machine, the usual feed pinion l4 meshing with said rack, the usual escapement wheel 15, the usual fore and aft extending shaft l6 journaled in the framework I0 and to which said wheel and pinion are fixed, the usual escapement dog rocker ll oscillative about the fixed horizontal pivot I'Ia which extends transversely of the machine, and the usual pair of escapement dogs l8 and I9 which alternatively engage with teeth of the escapement wheel in the normal and rocked positions of the dog rocker in the usual manner, the dog It being the usual stepping dog over which the escape ment ratchet wheel I5 is adapted to ratchet as usual when the carriage is back spaced. I I'he known machine also has a back spacing element or dog 20 of bellcrank form pivotally connected by a pivot 2| (extending fore'and aft of the machine) to the upper end of an arm 22,.

the arm 22 being pivotally held at its lower end to the framework l0 bya fore and aft extending pivot 23. The dog 20 has an arm pendent from its pivot and an arm extendingv leftward fromj its pivot, the latter arm having a reduced left hand end portion 20a slidably guided in a vertical slot 24 in framework l0. Slot 24 is closed at its lower end. The usual return spring 26.15113 connected to framework l0 and arm 22 to nor-' mally hold the dog 20 and arm 22 in the idle position shown in Figure 3. In this idle position of dog 20, the usual rightwardly facing stop shoulder 200, formed on the dog above pivot 2|,- is engaged with the usual stop lug 21 'onthe framework I0, the end portion 20a ,of the dog is seated on the bottom wall of slot 24 with theusual upstanding rack teeth 26 of the dog 'dis-' engaged from the teeth of the feed pinion l4, and the usual cam edge 20b of the dog is retracted rightward from slot 24. Cam edge 20b extends downward and rightward from portion 20a of the dog. The usual link Il, which extends transversely of the machine, is pivoted at its left hand end at I02 to the pendent arm of dog 20 and is pivoted at its right hand end at I03 to the upper end of the usual normally upstanding arm I04. The arm I04 and the usual bellcrank I05 are both loosely pivoted on a fore and aft extending pivot |06 carried on framework I0. The bellcrank hasan upwardly extending arm which is adjustably connected as usual to arm I04, said arm of the bellcrank having a slot |05a through which extends the shank of a clamping screw I01 which is threaded into arm I04 and clamps the arm and bellcrank to rock as a unit about pivot I06.

The improvements constituting the present invention are illustrated asembodied in power means for actuating the aforesaid backspacing dog of the known machine through. the aforesaid bellcrank and will now be described.

A power driven shaft 36, which extends h'orizontally transversely of the machine in the main framework I0 adjacent the 'rear end of the machine, is journaled in said framework at 31 and 38 and is constantly rotated clockwise (as viewed in Figure 2) by suitable power means while the machine is in use. Preferably, as shown, this constant power drive of shaft 36is effected by a small electric motor 39 mounted in the framework |0, which motor is constantly energized while the machine is in use and has a suitable speed-reducing driving connection 40 between its shaft 39a and the shaft 36. Small electric motors, such as employed in the machine shown,

rotate at high speed. While shaft 36 is driven.

by the motor through a reduction gearing, it still is driven at a high speed, a speed of approximately 400 R. P. M. having been found satisfactory for back spacing operations.

A single cycle clutch mechanism of the single revolution type is provided for transmitting power from the shaft 36 to impart back spacing movement to the carriage, said clutch mecha--' nism including a single control key 4| located in the keyboard of the machine. This clutch mechanism, which is of a special construction in the improved machine shown, will now be described.

The driving element of the clutch is a ratchet wheel 42 which is fixed on shaft 36 to rotate with the latter, and the driven element of the clutch is a ratchet dog 43 which is pivoted at 44 on a dog carrier 45 and is normally disconnected from the driving element. A suitablev torsion spring 46 constantly tends to rock dog 43 about its pivot into engagement with the ratchet wheel 42 for driving of the dog-43 and its carrier 45 by said wheel around the axis of shaft 36 in clockwise direction as viewed in Figure 2.

The driving and driven elements of the single cycle clutch mechanism are engageable to rotate the driven element and the dog carrier solely and exactly 360 degrees aboutthe axis of shaft 36 from a normal idle position in which said.

clutch elements are releasably disengaged and the dog carrier isreleasably locked against ronation in both directions about said shaft'axis.

A lever 6| is pivoted on a horizontal pivot 62 frame I0, and said lever is biased by a return spring 63 to move to a normal idle position in which a stop finger 64 on said lever is urged forwardly of the machine against a fixed stop part 66 of'the framework I0. At its upper end, said lever is provided with a laterally bent lug 66 for intercepting shaft-driven rotation of the dog carrier. Also pivoted on pivot 62 is a latch arm 61 between the free upper end of which and the lug .56 the reduced end portion 56 of the dog carrier is normally closely confined to latch the dog carrier in normal idle position against rotation in either direction. A spring 59 is connected to lever 5| and latch arm 51 to bias the latch arm to a normal latching position determined by a lug 60, which lug is formed on lever 5| for normal engagement therewith of the latch arm and to limit spring-urged movement of said arm. In the latched normal position of the dog carrier, the lug 56 on lever 6| is engaged with a tail portion 6| of clutch dog 43' to hold the nose of said dog out of engagement with the driving element (ratchet wheel 42) of the clutch.

A key lever 62 has an arm pendent from and pivoted on a fulcrum rod 63, and said lever has a, normally horizontal arm which extends forward from the pendent arm, substantially midway the upper and lower ends of said pendent,

arm, and is provided adjacent its forward end with an upstanding stem portion on the upper end of which the control key M is fixed. Thekey 4| is limited by engagement of the forwardly extending arm of the lever with the closed lower end of its guide slot. The key lever, and the means hereinafter described positively connected therewith, are held in normal idle position by a return spring 66 which is connected with the framework and the pendent arm of the key lever to yieldingly hold the key 4| in a normal elevated position in which a pendent stop lug 61 on the forwardly extending arm of the key lever is pressed forward against a straight return stop device 60 which extends horizontally transverse-- ly of the machine.

The fulcrum rod 63, preferably, is a straight rod which extends horizontally transversely of the machine to the rear of the keyboard, is fixed to framework l0, and crosses the slots of a straight horizontal row. of vertical guide slots 69 formed by power from shaft 36 in the manner and through the means disclosed in the application for United States patent of Charles Walker, filed November 26, 1943, Serial No. 466,989, and the dog rocker I'Lmaybe actuated by mean constructed as described in said application. The machine may also have its type bars (not shown) supported in a segment which is shiftable for case-changing by means disclosed in our application for United States patent filed February 9,

1943, Serial No. 475,264, and mayhave carriage return means and line spacing means constructed as disclosed in our application for United States patent filed May 20, 1943, Serial No. 487,686.

Journaled in the framework 18 substantially medially of the front and rear ends of the machine i a horizontal rock shaft 12 which extends transversely of the machine. Fixed on this shaft are two pendent rock arms 18 and 14, the arm 13 being substantially in fore and aft alignment with the pendent arm of key lever 62, and the arm 14 being substantially in fore and aft alignment with lever 51. A fore-and-ai't extending and normally horizontal link 15 connects the lower end of the pendent arm of the key lever with the lower end of rock arm 13. To the lower end of rock arm 14 a fore and aft extending and normally horizontal tappet bar 15 is pivoted at its forward end at 18 for swinging movement in a vertical plane. Tappet bar 18 is constantly guided intermediate its ends in a vertical guide slot 11 in stop part 55 of framework 1 8 and is normally held rocked up against the closed upper end of slot 11 by the spring 53 which is anchored to the lever 5| and to the'rear end of the tappet bar. To the rear of part 55 the tappet bar 16 is provided at its upper side with a rearwardly facing shoulder 18 which is normally located immediately forward of a laterally bent lug 88 formed on lever 5| below the fulcrumof said lever.

A mutilated pinion 41, 1oose on shaft 38 and loca'ted to the right of ratchet wheel 42, has its hub 41a extending through both the dog carrier 45 and an arm 48 and abutting the adjacent face of ratchet wheel 42. Arm 48 is fixed to the pinion hub 41a in a predetermined angularly adjusted position about the axis of the mutilated pinion 41, and the dog carrier 45 is fixed to said arm by a pin or rivet 49. The dog 48, dog carrier 45,

arm'48 and mutilated pinion 41 are thus rotative' return, under the influence of the hereinafter explained biasing force exerted thereon, to their normal idle positions during said single revolution of the pinion. Said demeshing of the rack lever and pinion preferably occurs (as in the construction shown) when the clutch element 48 and the pinion 41 have been rotated approximately with shaft 36 when dog 48 is engaged with ratchet wheel 42. I

A lever 86 ha its hub loosely journaled on shaft 38 and confined betweenthe mutilated pinion 41 and the shaft bearing or journal 38, said lever having a forwardlyfextending arm and a rearwardly xtending arm 'andbeing biased to move to a normal idle position in which a pin 81 on its rearwardly extending arm is seated on the upper edge of a stop lug 88 formed on framework 18. A segment rack lever 88 is pivoted inx-rmediate its ends on the framework at 88 to rock in the same vertical plane extending fore and aft of the machine in which the mutilated pinion 41 is located, said segment rack lever having a toothed forward arm andalso having a rear arm which is formed with a slot 81 which is radial to the fulcrum of the lever. The pin 81 is slidably engaged in slot; 8| and contacts both longitudinal walls of said slot. The segment rack lever is freely movable about its pivot 88 past the non-toothed portion of the periphery of mutilated pinion 41, but the normal stationary posi tions of the rack lever and pinion are suchthat, upon each revolution of the pinion, said pinion will first mesh with the teeth of said rack lever and rock the rack lever and lever 86 counterclockwise, as viewed in Figure 2, and clockwise as viewed in Figures 4 and 5, through a predetermined angle of rotation determined by the number of teeth on the pinion, and will thereupon demeshwith said rack lever before the pinion completes a single revolution and thus free both the rack lever and lever 88 for instant one-half of a revolution from normal position.

Pivoted to the forward end of the forwardly extending arm of lever 86 at 84, to rock fore and aft of the machine, is a pendent rm, 85. A spring 88 is connected with arm nd with a pendent extension of lever 88 to normally bias the rear arm of lever 88 down to engage pin 81 with lug 88. Spring 86 also constantly holds the arm 85 rocked rearward against the closed rear end of a fore and aft extending guide slot 88 in a part 88 of framework l8. The pendent arm 85 is formed atits lower end with a laterally bent lug I88 overlying tappet bar 18 and adapted, by

the aforesaid rocking of the lever from its normal idle position, to engage tappet bar 18 and swing it downwardly about its pivot 18 far enough to release lug 88 on lever 5| from shoui-. der' 18 on the tappet bar.

rock lever 5| and latch arm 51 into the position shown in'Figure 5, thusreleasing the clutch dog43 and its carrier 45, whereupon the dog 48 will be rocked by its biasing spring 46 into engagement with the driving clutch element 42, and the dog carrier and dog willthen start a driven revolutionabout the shaft axis in a clockwise direction,- as the parts are viewed in Figure 2, and counterclockwisedirection, as the parts are viewed in Figures 4 and 5. This driven movement of the dog and dog carrier imparts a like driven movement to the mutilated pinion 41 which pinion thereupon first meshes with the segment rack lever 88, rocks said lever 88 through a fixed are from its normal idle position, and then demeshes from the rack lever, all before the first revolution of the driven element of the clutch iscompleted, and will thereafter remain demeshed from the rack lever until the next cycle of operation of the clutch.

The aforesaid fixed extent of rocking move ment imparted fromthe driven element of the clutch to rack lever 88 also rocks lever 88 through pin 81 a fixed extent from the normal idle position of said lever 88, thus depressing arm 85 a fixed extent from its idle position to cause lug I88 on said arm to rock tappet bar 18 downward about its pivot 18 a fixed extent suflicient to free the lug 88 on lever 5| from shoulder 19 on the tappet bar before the mutilated pinion demeshes from segment rack lever 88. As

soon as the demeshing of the pinion and rack letheir normal positions to render them eflective to disengage the clutch dog 48 and hold it disengaged and to also look the dog carrier ,45 at the end of a 360 degree driven rotation of the dog carrier from its normal idle position, there- 'by also looking the mutilated pinion n in its normal position after a 360 degree rotation thereof. Springs 66 and 53 will restore the key lever and tappet bar to normal position whenever pressure is removed from the key. If pressure is removed-.from the key before arm 95 rocks tappet bar 18 out of engagement with lever 5|, the springs 80 and 53 will restore the manually shifted parts "-82-15-13-12-14-40 to idle position, but the clutch will nevertheless complete its cycle of operation and disengage.

The leftwardiy extending arm of the bellcrank- I05 is connected by an up and down extending link I08 with the pivot 94 carried by lever 86 of the clutch mechanism. The return springs. 26 and 96 bias dog 20, arm 22, link IOI,'arm I04, bellcrank I05, link I08, lever.06,'segment rack lever 90- and arm 95 to normal idle position, the idle position of said parts being determined by frame stops 08 and 21. The stop 88. is adjustably bendable up and down, and the push-pull connection between the dog 20 and lever 88 is extensibly adjustable at Ill-Ilia. The stop portion I6 of key lever 62, and the-lower portion of the pendent arm of said key lever, are both adjustably bendable fore andaft ofthe machine, and the stop portion 54 of lever Si is also adjustably bendable fore and aft of the machine.

The embodiment of the invention shown provides an actuating train between the back spacing dog and the driven element of the normally disengaged cyclic clutch, which train is so constructed that power transmitted from shaft I8 through said clutch imparts a complete back spacing movement of fixed extent to the dog 20 to back space the carriage one letter space durmg each cycle of operation of said clutch, and also that a complete power-actuated vibrative or reciprocative cycle of operation of said dog20 is effected substantially instantly and during each cycle of operation of said cyclic clutch.

During the first part of each cycle of operation of the clutchythe link I08 will bepulled down a fixed extent by power from shaft 36 and impart a fixed working stroke to dog 20, whereupon the link will rise and the dog will return to normal idle position during the latter part of the cycle of operation of the clutch. On its working stroke the'dog 20, as in the known machine, rocks on its pivot until itsgteeth 25 mesh with the teeth of feed pinion I6 and then moves leftward to the end of the stroke to rotate pinion It to reversely drive the carriage slightly more than one letter space but less than two letter spaces. At the end of the working stroke of the dog, the cam edge 20b thereon rides on the framework adjacent the bottom of slot 24 to jam the dog between the bottom of said slot and the pinion and thereby.

prevent momentum of the carriage from moving the carriage reversely more than the desired distance. The slight excess of back spacing movement of the carriage is for the usual purpose of insuring entry of the escapement dog I between the proper two teeth of the escapement ratchet wheel I before back spacing dog starts its return stroke. On its return stroke, the dog 20 swings down out of mesh with the feed pinion which is then held again by the engagement of escapement dog I8 with ratchet wheel I5, as

back spacing operations since the back spacing dog has a full and exactly predetermined working stroke impartedto it during the first half (or slightly more) of each revolution of the driven element of the single-revolution clutch and re turns to normal position during the remainder of the revolution of said element, which element is in turn rotated by the high speed power shaft.

trol the throw of the dog by duration of clutch engagement, and provides for actuation of the dog on its working stroke by power transmitted from a high speed power-shaft by a positive clutch and for return of the dog by spring means.

We'claim: 1. In a typewriting machine, a back spacing -mechanism comprising, in combination, a back spacing dog, a reciprocative rack positively connected with said dog, means biasing said dog and rack to a normal idle position, a power shaft which is joumaled in the machine and is conposition to its bias to impart a fixed working v stroke to. the dog, and finally to demesh from the rackprior to completion of said revolution and remain demeshed until the next revolution of the pinion. v

2. In a typewriting or like machine having a carriage back spacing element mounted therein for working and idle return strokes respectively I from and to a normal position in which said ,ele-

ment is disconnected from a reciprocal carriage usual, and the dog 20 finally moves rightward to idle position.

It will be observed that the construction shown and described provides for very rapid successive which is advanceable under control of an escapement, means for actuating said element on its working and idle return strokes comprising, in combination, a shaft which is constantly rotated by power while the machine is in use, a mutilated pinion; means to connect the shaft with the pinion to drive the pinion through a single revolution only and to thereupon automatically disconnect the 'shaft and pinion and arrest the pinion in a normal idle position thereof, a reciprocal rack drivable from a normal idle position by said pinion during each revolution of the pinion by the shaft, said pinion being so toothed as to mesh with. said rack during only an intermediate portion of each revolution of the pinion, means to drive said element on its working stroke through the medium of said rack while said pinion is in mesh with the rack, and means for constantly biasing said element and rack to move to their respective normal idle positions.

' 3. In a typewriting or like machine having a conversely movable member drivable in one direction to back space a reciprocal carriage which is positively connected with said member and is advanced under control of an escapement, power actuated means for driving said member one step at a time in said one direction comprising, in combination, a mutilated pinion rotative about a fixed axis, key-controlled power means for cycling said pinion througha single revolution and arresting the pinion in a normal definite stop position each time the control key of said power aav'aoss means is actuated, biased driving means roias tative means during only an intermediate pormember movable in opposition to its bias to drive f said member in said one direction and movable under its biasing influence to disengage from said member and return to a normal idle position, and

stop means to arrest biased movement of said cal rack with which said pinion first meshes and 1 then demeshes once during each revolution of the pinion to first move said biased driving means in opposition to its bias and to then permit biased movement of said driving means to the normal idle position thereof determined by said stop means. 1 I I 4. In a typewriting or like machine having a toothed element whichis conversely movable in response to retraction and escapement-controlled advance of a reciprocal carriage of the machine, key-controlled power actuated mechanism for actuating said element to back space the carriage comprising, in combination, a driving clutch element which is constantly rotated about a fixed axis while the machine is in use, a driven clutch element biased to engage the driving clutch element, means rotative about said axis and carrying said driven clutch element, means biased'to disengage the driven clutch element from the driving clutch element and hold the driven clutch element and said rotative means in a definite stop position thereof against rotation in both direcrarily disconnect said tappet device from said disengaging and holding means once during each revolution of said rotative means, biased impelling means for said toothed element engageable and drivable in opposition to its bias by said roimpel the toothed element in carriage back spac tion 01' each revolution of said rotative means to ing direction and movable by its bias to a normal idle position when disengaged from said rotative means, and stop means for arresting biased movement of said impelling means.

5. In a typewriting or like machine having a reciprocal'carriage advanceable under control of an escapem'ent, key-controlled power actuated mechanism for back spacing the carriage comprising, in combination, a clutch having driving and driven elements biased to engage, power means for constantly rotating the driving clutch element while the machine is in use, means biased to a disengage the clutch elements and arrest the driven clutch element in a single definite stop position, a key-operated device biased to a normal position from which it is movable by finger pressure to move and hold said biased means against its bias in a position permitting engagement of the clutch elements and rotation of the driven clutch element, means operable once by each revolution of the driven clutch element to back space'the carriage, and means operable by revolution of the driven clutch element to temporarily render said key-operated device ineffective on said biased means once during each revotions about said axis, a key-operated tappet delution oi said element.

6. A typewriting or like machine, as claimed in claim 5, wherein the means operable once by each revolution of the driven clutch element to back space the carriage comprises a member connected withthe driven clutch element to rotate in unison therewith, and a reciprocal member biased to a normal idle position and engageable and drivable in opposition to its bias by said rotative member during only an intermediate portion of each revolution 01' said driven clutch element and said rotative member to back space the carriage.

- CHARLES WALKER.

WILLARD H. WADE. 

